Plug-in device



FIG. 1 is a rear elevational view of a plug-in device showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is an elevational view of the right side thereof, with the left side being a mirror image thereof;

FIG. 4 is a top elevational view thereof; and,

FIG. 5 is a bottom elevational view thereof. 

CLAIM The ornamental design for a plug-in device, as shown and described. 